1. Field of the Invention
The present invention generally relates to jigs for semiconductor substrates and methods for manufacturing semiconductor devices using the same, and more particularly to a method of manufacturing a semiconductor device including a step of back grinding the back surface of the semiconductor substrate (wafer), a step of dicing for singularizing into semiconductor elements, and a step of bonding including picking up such singularized semiconductor elements and mounting them to the mounting device; as well as to a jig for semiconductor devices used for such a method.
Recently, with the necessity for semiconductor packages to be light, thin, short and small, the related wafers are also becoming thinner.
In each step such as in the back grind step, when the thickness of the wafer is less than 100 xcexcm, the wafer transportation and the semiconductor manufacturing process are technically very difficult using conventional methods. For this reason, a method of securely transporting and performing the process of semiconductor manufacturing with thinner wafers is desired.
2. Description of the Related Art
Conventionally, in manufacturing steps consisting of back grinding the semiconductor substrate (hereinafter also referred to as the wafer), singularizing the wafer into semiconductor elements by dicing, and bonding the singularized semiconductor elements on, for example, the mounting substrate, the transportation and the predetermined processes are carried out with the wafer attached to a tape. Each manufacturing step is described with reference to FIG. 1.
First, as shown in FIG. 1A, a circuit-forming surface is attached to a protection tape 2(attachment step). Subsequently, as shown in FIG. 1B, the wafer 1 is installed to a chuck table 4 and the back surface of the wafer 1 is back grounded by a rotating grind whetstone 3 (back grind step). As a result, the wafer 1 is thinned.
Secondly, a die attach film (not shown) is attached to the back surface of the thinned wafer 1(die attach mount step).
Subsequently, as shown in FIG. 1C, as the protection tape 2 attached to the wafer 1 is peeled, the back surface of the wafer 1 is attached to a dicing tape 6 (tape reapplication step). The dicing tape 6 is previously arranged in a frame 5 having a shape of a frame.
Next, as shown in FIG. 1D, the wafer 1 is cut along the predetermined dicing line using a dicing saw 7, and the wafer is singularized into semiconductor elements 10 (singularization step).
The singularized semiconductor elements 10 are pressed on their back surfaces through the dicing tape 6 using a push up pin 11 and as a result, the semiconductor elements 10 are peeled from the dicing tape 6, as shown in FIG. 1E. A collet 8 is located opposite the push up pin 11 on the upper side, and the peeled semiconductor elements 10 are adsorbed to and held by the collet 8 (pick up step).
The semiconductor elements 10 held by the collet 8 are transferred to the mounting substrate 9 as the collet 8 moves, and are bonded to the predetermined position on the mounting substrate 9 by the die attach film (bonding step). Through these steps, the semiconductor elements 10 formed on the wafer 1 are thinned and singularized, and then mounted on the mounting substrate 9.
The wafer 1 made extremely thin by the back grind step warps, which was not a problem with a conventional thickness. The thinning of the wafer 1 is not only the direct cause of reduction in the absolute strength of the wafer. When the wafer 1 warps, the performance of each manufacturing step after the back grind step is degraded, and along with transportation of the wafer becomes a factor of breakage failure.
This is significant particularly in the tape reapplication step. In other words, during the tape application, bubbles are likely to enter between the wafer 1 and the dicing tape 6 if the wafer 1 is thin.
When bubbles enter, the wafer 1 and the dicing tape 6 do not adhere at the locations where bubbles exist, and thus the adhesive strength between the wafer 1 and the dicing tape 6 decreases. Furthermore, when heat is applied, the bubbles expand and the wafer 1 and the dicing tape 6 are further separated from each other. Therefore, when bubbles enter, there is a possibility that an appropriate process may not be successfully performed in the steps subsequently conducted (for example, the singularization step), and the yield of the semiconductor manufacturing process is lowered, and in the worst case, the wafer 1 may break due to the expansion of bubbles.
On the other hand, in considering peeling the protection tape, the wafer 1 may break when the protection tape 2 is being peeled, or the wafer 1 may be peeled from the periphery at the start of peeling, and then break.
In view of the above problems, the general object of the present invention is to provide a jig for holding the semiconductor substrate so that there is little effect from thinned semiconductor substrates, and for suppressing the occurrence of damage caused by lack of semiconductor substrate strength; and to provide a method of manufacturing a semiconductor device using the jig.
The above object of the present invention is achieved by the following measures of the present invention.
The object of the present invention is achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig, wherein a method comprises the steps of fixing a semiconductor substrate flatly to a semiconductor substrate jig so as to prevent warps from occurring in the semiconductor substrate; and dicing the semiconductor substrate into a plurality of semiconductor elements while fixed to the semiconductor substrate jig.
According to this invention, since the semiconductor substrate is fixed to the semiconductor substrate jig without warps, the dicing step of the semiconductor substrate can be carried out smoothly.
The object of the present invention is further achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig comprising the steps of fixing a semiconductor substrate flatly to the semiconductor substrate jig so as to prevent warps from occurring in the semiconductor substrate; and back grinding the semiconductor substrate while attached to the semiconductor substrate jig.
According to this invention, since the semiconductor substrate is fixed to the semiconductor substrate jig without warps, the back grind step of the semiconductor substrate can be carried out smoothly.
The object of the present invention is achieved by a semiconductor substrate jig used for arranging a film on a semiconductor substrate, wherein the jig has a frame, an expandable member arranged within the frame and increasing or decreasing volume while deforming a shape by being supplied with fluid therein; and the shape is deformed so that the film arranged between the semiconductor substrate and the expandable member presses against the semiconductor substrate as contacting portion of the expandable member to the film is enlarged outwardly from the center of the film as the volume increases.
According to the present invention, when the volume of the expandable member increases, the film arranged between the semiconductor substrate and the expandable member deforms so as to be gradually pushed toward the semiconductor substrate from the center outward, and thus the air (bubbles) between the semiconductor substrate and the film is pushed outward from by the center outward as the expandable member deforms.
Therefore, the bubbles are prevented from remaining between the semiconductor substrate and the film, and the subsequent manufacturing steps are conducted smoothly and thus the breakage failure of the semiconductor substrate caused by the bubbles is prevented.
The above object of the present invention is also achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig described above, wherein the method has steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
back grinding a back surface of the semiconductor substrate while attached to the semiconductor substrate jig;
reapplying and fixing the semiconductor substrate to a second semiconductor substrate jig so as to expose the circuit-forming surface;
singularizing the semiconductor substrate fixed on the second semiconductor substrate jig into a plurality of semiconductor elements by dicing; and
picking up each of the singularized semiconductor elements from the second semiconductor substrate jig.
According to the above method of the present invention, since the semiconductor substrate jig is used, the bubbles are prevented from remaining between the semiconductor substrate and the first adhesive tape, and the semiconductor substrate is securely held to the semiconductor substrate jig in the back grind step. Thus, the back grind step is conducted smoothly.
The object of the present invention is further achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig, wherein the method comprises the steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
back grinding a back surface of the semiconductor substrate while attached to the semiconductor substrate jig;
singularizing the back grounded semiconductor substrate fixed on the semiconductor substrate jig into a plurality of semiconductor elements by dicing;
reapplying and fixing all of the semiconductor elements on a second semiconductor substrate jig so as to collectively expose the circuit-forming surface; and
picking up each of the singularized semiconductor substrates from the second semiconductor substrate jig.
As described above, after the back grind step is completed, the tape reapplication step may be conducted before or after performing the singularization step.
The object of the present invention is furthermore achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig described above, wherein the method comprises the steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
back grinding a back surface of the semiconductor substrate while attached to the semiconductor substrate jig;
singularizing the back grounded semiconductor substrate fixed to a second semiconductor substrate jig into a plurality of semiconductor elements by dicing; and
picking up each of the singularized semiconductor elements from the second semiconductor substrate jig and turning the picked up semiconductor elements upside down.
According to the above method of the present invention, since the tape reapplication step does not exist, the damage to the semiconductor substrate is prevented and there is no possibility of bubbles entering between the semiconductor substrate and the adhesive tape at the time of reapplication.
The object of the present invention is also achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig described above, wherein the method comprises the steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
singularizing the semiconductor substrate fixed on the semiconductor substrate jig into a plurality of semiconductor elements by dicing;
back grinding collectively back surfaces of plural semiconductor element attached to the semiconductor substrate jig;
reapplying and fixing the semiconductor elements collectively to a second semiconductor substrate jig so as to expose the circuit-forming surface; and
picking up each of the semiconductor elements from the second semiconductor substrate jig.
The object of the present invention is achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig described above, wherein the method comprises the steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
singularizing the semiconductor substrate fixed on the semiconductor substrate jig into a plurality of semiconductor elements by dicing;
back grinding back surfaces of plural singularized semiconductor elements attached to the semiconductor substrate jig; and
picking up each of the singularized semiconductor elements from the second semiconductor substrate jig and turning the picked up semiconductor elements upside down.
When the above method is used, by conducting the back grind step after the singularization step is completed, the strength of the semiconductor element is increased. Further, because the reapplication step is excluded, the damage to the semiconductor element and the entering of bubbles between the semiconductor element and the adhesive tape are prevented.
The object of the present invention is achieved by a semiconductor substrate jig used for arranging a film on a semiconductor substrate, wherein the jig comprises:
a frame with a bottom;
a set of plural annular members arranged concentrically within the frame and constructed so as to be individually movable in a direction perpendicular to the semiconductor substrate, the height of the annular members in the direction perpendicular to the semiconductor substrate gradually increasing from an outer circumference toward an inner circumference;
a biasing member for biasing each of the annular members toward the bottom of the frame; and
an operating member contacting the annular members by operating movement in the frame and provided for biasing in a direction separating the annular members from the bottom of the frame against the bias force of the biasing member; wherein
each of the annular members moves so as to gradually presses the film arranged between the semiconductor substrate and the set of annular member toward the semiconductor substrate from center outward with the operation of the operating member.
According to the above method of the present invention, with the operation of the operating member, each annular member is independently moved and gradually presses the film toward the semiconductor substrate from the center outward. Thus, the air (bubbles) between the semiconductor substrate and the film is pushed from the center outward with the movement of the annular member.
Therefore, the bubbles are prevented from existing between the semiconductor substrate and the film, and the subsequent manufacturing steps are smoothly conducted and the damage to the semiconductor substrate caused by the entering of the bubbles is prevented.
The object of the present invention is achieved by a method of manufacturing a semiconductor device using a semiconductor substrate jig, wherein the method comprises the steps of:
attaching a circuit-forming surface of the semiconductor substrate to the semiconductor substrate jig using a first adhesive tape as the film;
back grinding a back surface of the semiconductor substrate while attached to the semiconductor substrate jig;
die attach mounting for arranging die attach material to the back surface of the semiconductor substrate;
reapplying and fixing the semiconductor substrate on a second semiconductor substrate jig and exposing the circuit-forming surface;
singularizing the semiconductor substrate fixed on the second semiconductor substrate jig into a plurality of semiconductor elements by dicing; and
picking up each of the singularized semiconductor elements from the second semiconductor substrate jig.
According to the above method of the present invention, the entering of bubbles between the semiconductor substrate and the first adhesive tape is prevented, and the semiconductor substrate is securely held by the semiconductor substrate jig in the back grind step. Thus, the back grind step is conducted smoothly.
The object of the present invention is achieved by semiconductor substrate jig used in arranging a film to a semiconductor substrate, wherein the jig comprises:
a frame;
a porous member arranged within the frame so as to be opposite the film; and
a vacuum hole formed in the frame and provided for applying negative pressure to the porous member.
With the above semiconductor substrate jig, it is possible to prevent bubbles from entering between the film and the semiconductor substrate because the film is adsorbed to the semiconductor substrate jig through the negative pressure applied to the porous member and thus the film is planed.
The object of the present invention is achieved by a method of manufacturing a semiconductor substrate comprising the steps of:
attaching a circuit-forming surface of the semiconductor substrate to a semiconductor substrate jig that transmits light using a double-sided tape applied with an adhesive having ultraviolet curing properties on both sides;
back grinding a back surface of the semiconductor substrate attached to the semiconductor substrate jig;
irradiating ultraviolet rays to adhesives having the ultraviolet curing properties through the semiconductor substrate;
reapplying for arranging die attach film to the back surface of the semiconductor substrate, reapplying and fixing the semiconductor substrate to a second semiconductor substrate jig, and then exposing the circuit-forming surface;
singularizing the semiconductor substrate fixed on the second semiconductor substrate jig into a plurality of semiconductor elements by dicing; and
picking up each of the singularized semiconductor elements from the second semiconductor substrate jig.
According to the above method of the present invention, as the material that transmits light is selected to be used as the semiconductor substrate jig, ultraviolet rays can be irradiated to the adhesives with the properties of ultraviolet curing through the semiconductor substrate jig in the tape reapplication step even if the back grind step is conducted with the semiconductor substrate adhering to the semiconductor substrate jig.
The object of the present invention is achieved by a semiconductor substrate jig comprising
a first jig having a first suction mechanism sucking the semiconductor substrate; and
a second jig having a second suction mechanism sucking the semiconductor substrate;
the first and second jigs being removably constructed and independently sucking the semiconductor substrate.
According to the above jig of the present invention, because the first and the second suction mechanisms can independently suck the semiconductor substrate, the semiconductor substrate can be mounted independently to the first or the second jig. Thus, when the first jig and the second jig are combined, the semiconductor substrate can be suctioned using the first suction mechanism and the second suction mechanism.
Therefore, in case suction is switched from the first suction mechanism to the second suction mechanism, the suction of the second suction mechanism starts while the first suctioning mechanism is still suctioning, and then the suction by the first suction mechanism is released, thus the semiconductor substrate is constantly suctioned. The semiconductor substrate is prevented from warping because the semiconductor substrate is held either by the first or the second jig even if the semiconductor substrate is thinned.